Oral plaque consists of a wide variety of bacterial species embedded in a structural and functional matrix, called a biofilm. In addition to the bacteria, a variety of extracellular components are essential to the structure and function of this biofilm. Extracellular components of the plaque biofilm include: carbohydrates, nucleic acids, lipids, structural proteins, adhesins and signaling molecules. All of these components perform roles in maintaining structure of the biofilm or facilitating the transfer of signals and nutrients throughout the community. Traditional methods of oral cleaning have focused on the removal or killing of bacteria. Mechanical debridement through brushing and flossing removes all or part of the accumulated plaque. Chemical agents, such as cetylpyridinium chloride or triclosan usually focus on killing the bacteria embedded within the biofilm. However the non-bacterial components of the matrix are integral to the structure and function of oral biofilms and provide attractive targets for plaque disruption. Disruption of the extracellular components of the biofilm would physically break-up the plaque and, therefore, disrupt the protection provided by the biofilm. This would facilitate the physical removal of biofilm from hard to reach surfaces. Additionally, bacteria would then be more vulnerable to traditional methods of mechanical removal and chemical antibacterial treatments.
Numerous previous studies have identified enzymes as being potentially valuable for the removal of oral biofilms. However, use of enzymes in oral care formulations presents several challenges. While many enzymes are available, some enzymes and combinations of enzymes are much more effective than others for this use, and it is desirable to identify optimal combinations. Moreover, enzymes are generally commercially available in powdered form, as they are often unstable in liquid form. Using powdered enzymes in a mass manufacturing environment is difficult, as it is hard to measure and control the enzyme amounts accurately and maintain a safe working environment. Moreover, enzymes may present formulation and stability issues when incorporated into oral care products. The relative complexity of dentifrice formulations means that there are a large number of components that have the potential to interfere with the activity and stability of enzymes, and also the enzymes may in some cases degrade other formulation components. Finally, some people may have allergies or other sensitivity to particular enzymes, thus requiring alternatives to existing enzyme formulations.
Therefore, there is a need for stable enzyme preparations that are able to disrupt dental plaque and can be easily incorporated into oral care compositions.